PLEASE HELP: horn trigger wiring

Edit: Also if this is in the wrong category please let me know and I’ll be happy to move it. Thanks

So I have a 2014 Tundra Platinum CrewMax and I’ve just installed a 12voltsolutions plug and play remote start kit. Everything was very well made, from the full plug and play bungs, to the tesa taped harnesses, and the dielectric grease in every pigtail. Fantastic product and couldn’t be happier.

But I do have one question and I’m hoping you guys can help me figure it out. I’ve been a audio/alarm installer for over 10 years and I have tons of viper and compustar sirens laying around that customers didn’t want installed. I’m wondering if there is a way to change the tundra factory alarm horn trigger wire to run to a siren instead? If so what wire would I use and is it a switched positive or negative? Also if doing this will effect the function of the factory horn through the steering wheel.